a. Field of the Invention
The invention relates to devices for weighing objects. In particular, the invention relates to adaptors which allow a person in a wheelchair, with the aid of an assistant, to be weighed on a typical bathroom-type scale. The invention includes a portable wheelchair scale adaptor platform adapted to be received upon a typical bathroom scale, and an access ramp attached thereto to allow a wheelchair-bound person, with the aid of an assistant, to be rolled onto the platform thereby measuring his weight.
b. Description of the Prior Art
Numerous devices to allow a wheelchair-bound person to be weighed without removing them from their chair are known prior art. These devices are typified by U.S. Pat. No. 5,448,022 to Richel for a Tip-On Wheelchair Scale Adaptor, U.S. Pat. No. 4,126,197 to Kechely for a Weighing Ramp Adaptor, U.S. Pat. No. 3,30,299 to Albagli for a Platform Weighing Scale and Loading Adaptor therefor, and U.S. Pat. No. 3,732,938 to Nelson for a Wheelchair Weighing Platform. Richel's Tip-On Wheelchair Scale Adaptor cannot be used without assistance from someone other than the person in the wheelchair. The frame disclosed by Richel is first placed on the weighing scale. The wheelchair is then positioned in front of the lateral edge of the platform and the assistant tips the wheelchair backwardly to allow the front wheels of the wheelchair to pass over the platform. Once the front wheels of the wheelchair are over the platform, the wheelchair is tipped forward into its normal position which causes the lower frame member of the wheelchair to rest on the weighing platform. The wheelchair is thus held off the ground by the lower member of the wheelchair resting upon the weighing platform, and the person's weight can be recorded. The drawback with Richel, however, is two-fold; (1) a user in a wheelchair cannot weigh himself without assistance from another; and (2) the readout from the dial on the weighing scale is obscured by the wheelchair device itself so that the user in the wheelchair cannot see the readout of the weighing scale.
The device disclosed by Kechely is very simple. The device rests on the platform of the weighing scale, so that when a user places the front wheels of a wheelchair on the leading edge of the platform it tips forward presenting an angled surface onto which a user rolls the wheelchair. Once the user is all the way up on the platform, it angles back down to where it rests on the platform of the weighing scale. At that point, the weight of the patient can be noted. Again, the patent refers to use with an attendant of this device. The assistant to the person in the wheelchair tips the device so that the front edge is against the ground and the wheelchair can be rolled up onto the device. In addition, the assistant to the wheelchair-bound person would be the person to read the scale since the wheelchair-bound person could not see the readings of the scale. Another problem with Kechely is that older patients who are uncomfortable with unstable devices may be unwilling to wheel up the ramp for fear that their wheelchair will tip over backwards. The device wobbles substantially as the patient is wheeling himself onto the platform.
The same disadvantages apply to Nelson. None of these devices present a stable platform for a user to roll the wheelchair onto. The platform rests on the scale and tips and moves during operation. Wheelchair-bound patients, particularly older patients, may be uncomfortable with this tipping and unstable motion.